1. Field of the Invention
The present invention relates to a pump system provided with a plurality of hydraulic pump bodies and a PTO unit.
2. Related Art
A pump unit, which is provided with a single input shaft, a plurality of pump shafts operatively connected to the input shaft, a plurality of hydraulic pump bodies to be driven by each of the plurality of pump shafts, a PTO unit that is operatively connected to the input shaft and has a PTO shaft, a pump case for accommodating the plurality of hydraulic pump bodies and the PTO unit and supporting the input shaft, the plurality of pump shafts and the PTO shaft, and a port block (or a center section) connected to the pump case, has been conventionally used in various fields (for example, refer to JP-A 2003-291674).
More specifically, according to this conventional pump unit, it is possible to configure a first transmission path including the plurality of hydraulic pump bodies and a second transmission path including the PTO unit from a single input path by operatively connecting the input shaft to a driving source by way of an input transmission mechanism, with the pump case connected to a supporting member such as a vehicle frame.
Accordingly, this pump unit is particularly available for a working vehicle or the like requiring two transmission paths including a traveling transmission path and a PTO transmission path.
However, in the conventional pump unit, there is room for improvement in workability of replacement and workability of maintenance of the hydraulic pump bodies.
In other words, in this conventional pump unit, the pump case is connected to the supporting member such as the vehicle frame or the driving source.
Accordingly, in the case of carrying out the replacement or maintenance operations of the hydraulic pump body, it is necessary that the pump unit including the input shaft is entirely separated from the supporting member or the port block is separated from the pump case.
According to the former method, it is necessary that the engagement between the input shaft and the input transmission mechanism is released and the engagement between the PTO shaft and a transmission shaft following thereto is also released.
According to the later method, it is necessary that the port block is separated from the pump case with the pump case connected to the supporting member such as the vehicle frame. Therefore, the operability is not good and it is feared that the parts configuring the hydraulic pump bodies and the PTO unit drop out against a user's will.
The present invention has been made taking the foregoing problems into consideration, and an object thereof is to provide a pump system having hydraulic pump bodies and a PTO unit, the pump system being capable of efficiently carrying out the replacement work and the maintenance work of the hydraulic pump bodies.